src/mem_node.cc

   1
   2 /*
   3  * $Id$
   4  *
   5  * DEBUG: section 19    Store Memory Primitives
   6  * AUTHOR: Robert Collins
   7  *
   8  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   9  * ----------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from
  12  *  the Internet community; see the CONTRIBUTORS file for full
  13  *  details.   Many organizations have provided support for Squid's
  14  *  development; see the SPONSORS file for full details.  Squid is
  15  *  Copyrighted (C) 2001 by the Regents of the University of
  16  *  California; see the COPYRIGHT file for full details.  Squid
  17  *  incorporates software developed and/or copyrighted by other
  18  *  sources; see the CREDITS file for full details.
  19  *
  20  *  This program is free software; you can redistribute it and/or modify
  21  *  it under the terms of the GNU General Public License as published by
  22  *  the Free Software Foundation; either version 2 of the License, or
  23  *  (at your option) any later version.
  24  *
  25  *  This program is distributed in the hope that it will be useful,
  26  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  *  GNU General Public License for more details.
  29  *
  30  *  You should have received a copy of the GNU General Public License
  31  *  along with this program; if not, write to the Free Software
  32  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  33  *
  34  */
  35
  36 #include "squid.h"
  37 #include "mem_node.h"
  38 #include "protos.h"
  39
  40 static ptrdiff_t makeMemNodeDataOffset();
  41
  42 static ptrdiff_t _mem_node_data_offset = makeMemNodeDataOffset();
  43
  44 /*
  45  * Calculate the offset between the start of a mem_node and
  46  * its 'data' member
  47  */
  48 static ptrdiff_t
  49 makeMemNodeDataOffset()
  50 {
  51     mem_node *p = 0L;
  52     return ptrdiff_t(&p->data);
  53 }
  54
  55 /*
  56  * This is the callback when storeIOWrite() is done.  We need to
  57  * clear the write_pending flag for the mem_node.  First we have
  58  * to calculate the start of the mem_node based on the character
  59  * buffer that we wrote.  ick.
  60  */
  61 void
  62 memNodeWriteComplete(void* d)
  63 {
  64     mem_node* n = (mem_node*)((char*)d - _mem_node_data_offset);
  65     assert(n->write_pending);
  66     n->write_pending = 0;
  67 }
  68
  69 mem_node::mem_node(int64_t offset):nodeBuffer(0,offset,data)
  70 {}
  71
  72 mem_node::~mem_node()
  73 {}
  74
  75 size_t
  76 mem_node::InUseCount()
  77 {
  78     return Pool().inUseCount();
  79 }
  80
  81 size_t
  82 mem_node::StoreMemSize()
  83 {
  84     return InUseCount() * SM_PAGE_SIZE;
  85 }
  86
  87 int64_t
  88 mem_node::start() const
  89 {
  90     assert (nodeBuffer.offset >= 0);
  91     return nodeBuffer.offset;
  92 }
  93
  94 int64_t
  95 mem_node::end() const
  96 {
  97     return nodeBuffer.offset + nodeBuffer.length;
  98 }
  99
 100 Range<int64_t>
 101 mem_node::dataRange() const
 102 {
 103     return Range<int64_t> (start(), end());
 104 }
 105
 106 size_t
 107 mem_node::space() const
 108 {
 109     return SM_PAGE_SIZE - nodeBuffer.length;
 110 }
 111
 112 bool
 113 mem_node::contains (int64_t const &location) const
 114 {
 115     if (start() <= location && end() > location)
 116         return true;
 117
 118     return false;
 119 }
 120
 121 /* nodes can not be sparse */
 122 bool
 123 mem_node::canAccept (int64_t const &location) const
 124 {
 125     if (location == end() && space() > 0)
 126         return true;
 127
 128     return false;
 129 }
 130
 131 bool
 132 mem_node::operator < (mem_node const & rhs) const
 133 {
 134     return start() < rhs.start();
 135 }